1. Field of the Invention
This invention relates to a motion picture recording method, a motion picture recording medium, and a motion picture reproducing apparatus, and is suitable for application to the case where picture data composed of a plurality of motion pictures is recorded on art optical disc, and then is reproduced.
2 . Description of the Related Art
It is posited that, for example, scenes of a sports event, a concert or the like are taken by a plurality of video cameras, and the plurality of motion pictures thus obtained simultaneously are also recorded on an optical disc. During reproduction, the recorded optical disc is reproduced selectively, such that either a single motion picture taken by a predetermined video camera or a plurality of motion pictures is displayed. By such a display method, the user can enjoy a motion picture which is edited as desired. This differs from the conventional method in which a motion picture formed with previous editing is displayed.
Such a display method is realized by improvement of the compression encoding techniques for motion pictures, by which about five times as much motion picture data can be written on an optical disc which is the same size as a conventional one. This means that, even for the same reproducing time, a plurality of motion pictures taken by five video cameras can be recorded.
On the other hand, the track pattern of ordinary optical discs has been formed in a spiral, not in concentric circles, because in ordinary use, successive reproduction of one motion picture is most common.
When a plurality of motion pictures is recorded to such an ordinary optical disc, it is considered that each motion picture is recorded to each area at once. For example, when there are motion picture data a, b, . . . , e, taken by video cameras A, B, . . . , E, each motion picture data is sequentially disposed in the radial direction from the center of the optical disc.
By disposing data in such a manner, in ordinary reproduction in which the motion picture data taken by only one video camera is displayed, the optical pick-up may move ordinarily in a successive fashion.
While reproducing a predetermined motion picture (for example, the motion picture data a), if switching to reproduce another motion picture (for example, the motion picture data b), the recording position of the picture data of the motion picture b which corresponds to the recording position of the picture data of the motion picture a is obtained. The optical pick-up is track-jumped from the current position to the obtained recording position (within motion picture b), and then is switched to the reproducing state so as to display motion picture b.
However, as described above, in the case of an optical disc on which the picture data of a plurality of motion pictures are separately recorded to respective areas, at the time of switching from the recording area of a predetermined motion picture data to the other, the optical pick-up must obtain the recording position corresponding to the second picture data so as to track-jump. This occurs when these motion picture data are accessed one after another in order to be reproduced.
In this case, since the optical pick-up must cross completely the other recording area, the moving distance of the optical pick-up becomes longer.
Therefore, time elapses before reproduction of the other motion picture data begins. Thus, there: is the problem that it cannot time-successively reproduce from among a plurality of motion pictures.
Further, the calculation for obtaining the corresponding recording position is complicated. Thus, there is the problem that control of the reproducing apparatus becomes complicated.
Furthermore, because the moving distance of the optical pick-up is large and high speed track-jumping is required, a drive mechanism having a powerful optical pick-up is required.